Symbol 802.11 interfering with Cisco 802.11g

[zpetersen]

We currently have a facility wide 802.11 wireless network running off of Symbol's Spectrum 24 AP's. This system was installed about four years ago and like 802.11b/g uses 2.4 GHz frequencies.

Recently we installed a large quantity of Cisco 1200 series 802.11G AP's to support a new project. After a while we noticed a lot of strange connection problems plaguing the 802.11G network. After a bit of troubleshooting we came to the conclusion that the 802.11 frequency hopping Symbol equipment was interfering with the Cisco equipment.

Shortly after we came to this conclusion we unplugged the Symbol 802.11 access points and immediately noticed a huge gain in reliability from the Cisco AP's.

Here’s the question: Has anyone dealt with coexisting Symbol and Cisco wireless networks or any other DSS v. Frequency Hopping networks? Any clues as to where I might look for help on making these things live happily together? Even a band-aid solution would be great.

 

[vipergg]

You will have make a diagram of where you currently have your Symbol gear and what channel each wap is working on, you then have to try and configure the cisco gear in each area so that it is not conflicting with channels on the Symbol gear .This could be hairy if you have a lot of AP's in a given area . Obviously you are getting interference between the AP"S .A wireless sniffer would help in this case . You also will have to check your coverage area and try to make sure that you don't have the Symbol gear covering the same area as the cisco gear . Wireless is fun huh ????????????? I'll take wired for corporate connections .

 

[zpetersen]

Actually the problem is that the Symbol AP's run use Frequency Hopping Spread Spectrum (FHSS) and hop the entire 2.4 GHz spectrum. The cisco AP's are Direct Sequence Spread Spectrum (DSSS).

Its similar to if you have a 2.4 GHz cordless phone in a small 802.11b network.. the phone will wreak havoc on your network because it steps on the spectrum you are trying to use. So basically when the Symbol access points hop onto the same signal as the Cisco AP's down they go.

It would be very easy to fix if we could just adjust the hopping sequence of the Symbol AP's.. but as far as we can tell there is no way to do that. If we could we would set them at the low end of the spectrum and the cisco AP's at the high end.. and all would be well until we can replace the old symbol eq.